Servo brake



1930- R. s SANFORD 1,774,158

SERVO BRAKE Filed April 16. 1927 I N V EN TOR. 201 J- Jfi/YFOBW 1 -Patented Aug. 26, 1930 "UNITEDTSTTATES PATENT. QFFICE BOY s, 'smonn, or scorn BEN-D, IN ANA, nssrenon 'ro snnmx BRAKE comrm,

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. Application filed April 16, 1927. Serial No. 184,298.

My invention relates to an improved I servo brake. The objectisto provide in a vehicle having a power plant'to drive it, and brake mechanism to retard its travel, a

- 5 servo device associated with the brake mechanism and directly coupled with the power plant to be actuated thereby.

My invention is here illustrated as .embodied in servo brake mechanism on anautomobile having brakes associated with its wheels and an engine comiected therewith through a clutch to drive the same, which servo m'echanismis so constructed and arranged as to be controlled by the control member provided for the clutch whereby,

following the actuation of such control member to release the clutch the -servo mechanism is brought into action to apply the brakes. I

Servo devices have heretofore been employed wherein a connection was made with,

certain moving parts of the vehicle to take a power impulse therefrom to appl the brakes but in these cases the servo evice received its impulse due to the inertia of travel of the vehicle. In such a construction the applied braking force decreased as the vehicle was retarded. In the construction here shown the application of the servo is entirely independent of the rate of travel of the vehicle and depends rather uponthe speed of the engine and is directly controlled thereby. The vehicle, therefore,- might be rapidly decreasing in speed and et the servo device mi ht be constantly ringing a reater retanfing force to bear upon the ve 'cle.

Other advantageous features and meritorious objects of my invention will more fully appear from the following description, appended claims, and accompanying-drawing, whereinz 1 Fig. 1 is a side elevation of an automobile chassis including my invention, and

Fi 2 is a rear elevation of the engine provided with my improved servo device.

In the embodiment ofthe invention illustrated in the dra ,let 10 indicate a road vehicle havin whee 12 and an engine'l t.

These road w eels are provided brakes and an operating connection 16 leads thereto. The driving connection between the engine and the vehicle includes a clutch which is controlled-by the clutch pedal 18. The engine'shaft 20 carries a rotatable element,

which may be the flywheel 22, and a band 2ft, provided witha friction face 26, encircles this wheel. Opposite ends of the band are connected on opposite sides of a pivotal mounting 28 to the short arm of a bellcrank lever 30, the long arm of which is articulated throu h a link 32 with the clutch pedal 18 to e actuated thereby to tighten the band about the wheel upon depression of the clutch pedal; The pivot 28 is a floating one as it supports the bellcrank lever on the swinging link 29 which link is pivotally supported at 33. w

A bracket 3 1 is secured to the band 24 and the brake connection 16 is secured to the bracket '34'whereby, upon actuation of the band as it is actuated by the wheel when tightened thereabout, the brakes are applled.

The connection between the clutch pedal and the band 24 is such that the initial movement of the clutch pedal releases the clutch, disconnecting the-engine from driving engagement with the vehicle, and con tinued movement of the clutch pedal tightens the band about the fly-wheel and applies the brakes. It is therefore evident that an operator driving the vehicle may keep his right. foot on the accelerator and -the vehicle, a clutch. in the drivin p y the brakes.

rotatable element to be' actuated apply the brakes.

'2. A .vehicle having, wheels, brakes therefor,

thereby to in combination, an engine to drive conned,- ne, a clutch peda a servo tion with the en device connects I the brakes, said servo device havin one part coupled with the engine to be riven thereby at all times during the running of the en inc, and having another part coupled with t e clutch pedal to be actuated thereby to engage the part under control of the engine to apply the brakes but only after the clutch pedal has been actuated sufficiently torelease the clutch. i

3. A vehicle having, in combination, wheels brakes therefor, an engine to drive the vehicle, a clutch in the driving connec-' tion with the en inc, a servo device connected with the rakes and mechanically coupled with the engine to be actuated thereby to apply the bra es, and a single control member for the clutch device. I

- 4. A vehicle having, wheels, brakes therefor, an engine having a fly-wheel, a servo device connected with the brakes and including a band encircling the fl -wheel to be tightened thereabout to apand for the servo 5; A vehicle having, in combination, wheels, brakes therefor, an engine havin a drive-shaft connected through a clutch with the vehicle to drive the vehicle, a fly-wheel on the shaft, a band about the fiy-wheel, said band connected with the brakes to apply them, and a clutch pedal for controlling the clutch; said clutch pedal connectedwit the wheels, an

, mechanism, said servo device havl constantly thereby during the engine, with the clutch operating mechanism to be 'drivin the w eels, a servo device connected with hi the band to tighten the band about the flywheeltoa 6. A ve the brakes.

l 7 ii: having wheels, brakes for wheels to propel the vehicle, a clutch in the connection between the engine and the brakes and mechanically coupled with the engine to be' actuated thereby to apply braking ressure, and means connecting the clutch with the servo device whereby the servo device 0 rates to apply the brakes upon release 0 the. clutch.

7. A vehicle having wheels, brakes for the wheels, 'an engine connected thro h a clutch with the wheels to propel the ve 'cle, a servo device connected with the brakes and the engine to derive brake applying power from the engine, clutch 0 rating part connected with the engine to be riven the running of and a second part connected actuated thereby duri the disen ment of the clutch ng gage with the brakes to apply in combination,

engine connected with the to be coupled with the firstpart to be actuated thereby to apply the rakes clutch with the wheels to propel thevehicle,

a servo device connected with the brakes and the engine to derive brake applying power from the engine, clutch operating mechanism, said servo device having one part mechamcally coupled with the engine to .be

driven thereby during the running thereof and a second part coupled with the brakes to apply the brakes and with the clutch operating mechanism to be actuated thereby following a limited initial movement of the clutch, to engage the first part to be actuated thereby to apply the brakes.

9. A vehicle having wheels, brakes for the wheels, an engine connected with the wheels to propel the vehicle, said engine having a'fly-wheel, a servo device connected with the brakes and coupled with the flywheel to receive brake applying power therefrom and means operable to bring the servo device into engagement with the flywheel to derive power from the fiy-wheel and to disengage the same therefrom.

10. A vehicle having an engine to propel it and brakes to retard its travel, said engine having a fiy-wheel, and means operable to couple the brakes with the eriphery of the fly-wheel to receive bra e applying power therefrom. v

11; A vehicle having wheels, brakes for the wheels, an engine, means operable to releasably couple the engine with the wheels to propel the vehicle, and mechanism coordinated with said means to releasably cogple the engine with the brakes to deliver br e applying power thereto coincident with the disengagement of the driving connection between the engine and the wheels.

12. A vehicle having wheels, brakes for the wheels, an engine connected with the wheels througha clutch to propel the ve- 'cle, a servo device connected with thebrakes to exert brake applying force there-. on, and a single control member to bring the clutch and servo device jointly into operation, said servo device having one part mechanically connected with the engine to be constantly rotatably driven thereby during the running of the engine, and a second part connected with the brakes and with the single control member to be actuated thereby upen disengagement of the clutch to derive power from the first part to apply the brakes.

13; A vehicle having wheels, brakes forthe wheels, an engine connected with the wheels through a clutch to propel the vehicle, a servo ,device connected with the brakes to exert brake applying force thereon, control means operable todisengage v the clutch and ,upon the disengagement thereof to bring the servo device into operation to apply the brakes, said servo device having one part mechanically connected with the engine on the engine side of the clutch to be constantly rotatably driven thereby during the running of the engine,

and a second part connected with the brakes and with the single control member to be actuated thereby upon disengagement of the clutchto derive power from the first part to apply the brakes.

In testimony whereof, I, ROY S. SANFORD, sign-this specification.

ROY s. SANFORD. 

